The present invention relates to analog multiplexers, and more specifically, to pass gates included in an analog multiplexer.
Today's large computer chips still require many analog circuits to function correctly. Often it is necessary to multiplex between many of these analog signals from all across the chip, whether for characterization, debug or functionality. In previous technologies, a simple transmission gate multiplexer composed of transistors with thick gate oxides was used along with high voltage select lines to block the disabled paths. In today's technologies access to thick gate oxides can be limited or is not available. Since the device breakdown voltage of these conventional pass gates is often only around one volt, the maximum analog voltage of any of the multiplexor inputs must be known in order to implement these conventional pass gates.